Anesthesia and analgesia
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Anesthesia and analgesia · Feb 2002
Randomized Controlled Trial Clinical TrialThoracic epidural anesthesia for cardiac surgery: the effects on tracheal intubation time and length of hospital stay.
Improvements in analgesia after major surgery may allow a more rapid recovery and shorter hospital stay. We performed a prospective randomized trial to study the effects of epidural analgesia on the length of hospital stay after coronary artery surgery. The anesthetic technique and postoperative mobilization were altered to facilitate early intensive care discharge and hospital discharge. Fifty patients received high (T1 to T4) thoracic epidural anesthesia (TEA) with ropivacaine 1% (4-mL bolus, 3-5 mL/h infusion), with fentanyl (100-microg bolus, 15-25 microg/h infusion) and a propofol infusion (6 mg x kg(-1) x h(-1)). Another 50 patients (the General Anesthesia group) received fentanyl 15 microg/kg and propofol (5 mg x kg(-1) x h(-1)), followed by IV morphine patient-controlled analgesia. The TEA group had lower visual analog scores with coughing postextubation (median, 0 vs 26 mm; P < 0.0001) and were extubated earlier (median hours [interquartile range], 3.2 [2.1-4.6] vs 6.7 [3.3-13.2]; P < 0.0001). More than half of all patients were discharged home on Postoperative Day 4 (24%) or 5 (33%), but there was no difference in the length of stay between the TEA group (median [interquartile range], Day 5 [5-6]) and the General Anesthesia group (median [interquartile range], Day 5 [4-7]). There were no differences in postoperative spirometry or chest radiograph changes or in markers for postoperative myocardial ischemia or infarction. No significant TEA-related complications occurred. In summary, TEA provided better analgesia and allowed earlier tracheal extubation but did not reduce the length of hospital stay after coronary artery surgery. ⋯ We found that epidural analgesia was more effective than IV morphine for cardiac surgery. Epidural anesthesia also allowed earlier weaning from mechanical ventilation, but it did not affect hospital discharge time.
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Anesthesia and analgesia · Feb 2002
Randomized Controlled Trial Clinical TrialThe effect of nitrous oxide on jugular bulb oxygen saturation during remifentanil plus target-controlled infusion propofol or sevoflurane in patients with brain tumors.
During propofol/fentanyl anesthesia, a large percentage of patients have jugular bulb oxygen saturation (SjO(2)) <50%. The incidence is less with isoflurane/N(2)O. We evaluated the effect of N(2)O on SjO(2) during remifentanil-based anesthesia with concurrent propofol or sevoflurane in 20 adults undergoing brain tumor surgery. Anesthesia was randomized: Group 1 (n = 10), target-controlled infusion propofol; and Group 2 (n = 10), thiopental 2-3 mg/kg followed by sevoflurane 0.9% end-tidal. Jugular bulb and arterial blood samples for gas analysis were withdrawn during the administration of oxygen 33% with nitrogen 67% and then with N(2)O 67%. All samples were drawn before surgery and 20 min after the addition of the study gas and with an ETCO(2) 26-28 mm Hg and mean arterial pressure >90 mm Hg. Both groups had similar demographic and physiologic data. In the Propofol group, SjO(2) was 50% +/- 10% with nitrogen and 52% +/- 9% with N(2)O (not significant); in the Sevoflurane group, however, N(2)O 67% increased SjO(2) from 56% +/- 13% to 66% +/- 12% (P < 0.01). This indicates that N(2)O does not reduce the incidence of low SjO(2) values during propofol anesthesia. ⋯ This study demonstrates that nitrous oxide can increase jugular bulb venous oxygen saturation when added to sevoflurane/remifentanil anesthesia, but not to propofol/remifentanil anesthesia, in patients with brain tumors.
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Anesthesia and analgesia · Feb 2002
Randomized Controlled Trial Clinical TrialThe timing of intravenous crystalloid administration and incidence of cardiovascular side effects during spinal anesthesia: the results from a randomized controlled trial.
We conducted a randomized clinical trial to evaluate the efficacy of crystalloids in preventing spinal-induced hypotension (SIH) and cardiovascular side effects (CVSE) in a group of surgical patients. Participants were assigned to receive lactated Ringer's solution at 1-2 mL/min (Placebo group, n = 142); lactated Ringer's at 20 mL/kg starting 20 min before spinal block (n = 130); or lactated Ringer's at 20 mL/kg starting at the time of spinal block (n = 132). SIH was defined as a decrease of > or = 30% in baseline systolic blood pressure, and CVSE as SIH plus nausea, vomiting, or faintness requiring treatment. The incidence of SIH was similar in all treatment groups. Compared to placebo, crystalloid administration at the time of spinal block resulted in a significant reduction in the proportion of patients developing CVSE from 9.9% to 2.3%. The corresponding relative proportion was 0.23 (95% confidence interval, 0.07-0.78; P = 0.019), and one additional case of CVSE was avoided for each 13 patients receiving crystalloids at the time of spinal block instead of placebo. Administration of crystalloids at the time of spinal block seems to be effective because it provides additional intravascular fluids during the period of highest risk of CVSE after spinal anesthesia. ⋯ Crystalloids are frequently administered to nonobstetric patients minutes before spinal anesthesia to prevent cardiovascular side effects (CVSE). This randomized controlled trial shows that although crystalloids administered before spinal block result in no clinical benefit, they significantly reduce the risk of CVSE when administered at the time of spinal block.
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Anesthesia and analgesia · Feb 2002
Venous air emboli occur during release of positive end-expiratory pressure and repositioning after sitting position surgery.
We studied the effect of positive end-expiratory pressure (PEEP) release and positioning on the occurrence of venous air embolism (VAE). Eighteen consecutive patients (8 women, 10 men; ASA grade I-III) undergoing neurosurgery in the sitting position were studied. After induction of anesthesia ventilation was controlled with a PEEP of 5 cm H(2)O in an oxygen-air gas mixture. A transesophageal echocardiographic (TEE) probe was inserted. Preoperatively, a patent foramen ovale was excluded in all patients. TEE monitoring was performed during surgery, during PEEP release at the end of surgery with the patient still in the sitting position, and during change of the patient position into the supine position. The severity of VAE was differentiated as follows: grade 1 = only microbubbles; grade 2 = microbubbles and decrease of end-tidal carbon dioxide partial pressure (PETCO(2)) by more than 1.5 mm Hg; grade 3 = microbubbles combined with a decrease of PETCO(2) by more than 1.5 mm Hg, and a decrease of mean arterial blood pressure by at least 20 mm Hg. During surgery, VAE with a grade of 1, 2 or 3 occurred in 7, 4, and 2 patients, respectively. After PEEP release, VAE of grades 1, 2, and 3 were observed in 7, 2, and 1 patients, respectively. During repositioning from sitting to supine position, VAE of grades 1, 2, and 3 was observed in 6, 1, and 1 patients, respectively. The patient with VAE grade 3 needed inotropic support until 2 h after surgery to maintain sufficient blood pressure. No patient showed any sign of paradoxical arterial embolism or cardiac dysfunction. We conclude that VAE occurs not only during surgery in the sitting position, but also with release of PEEP and during repositioning to the supine position. ⋯ This study shows that venous air embolism (VAE) occurs not only during surgery in the sitting position but also during positive end-expiratory pressure release and repositioning of the patient into the supine position. Continuous monitoring for VAE should be performed until the patient is returned to the supine position.
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Anesthesia and analgesia · Feb 2002
Case ReportsDifficult retrograde endotracheal intubation: the utility of a pharyngeal loop.
Direct laryngoscopy and tracheal intubation remains the technique of choice to achieve control of the airway. Alternative or additional techniques of airway control are required whenever an airway is deemed difficult because of anatomical and/or technical reasons. The retrograde intubation technique is an important option for gaining airway access from below the vocal cords in such situations (1). We report successful management and the problems encountered while gaining the upper airway by the retrograde catheter method in a patient having bilateral fibrous ankylosis of the temporomandibular joint (TMJ). ⋯ A 30-yr-old woman presented for redo-release of bilateral temporomandibular joint ankylosis under general anesthesia. During the previous anesthetic for primary release of ankylosis, tracheostomy was done, as conventional blind nasotracheal and retrograde intubation attempts failed several times. This case report describes the method for overcoming the difficulties of a retrograde intubation procedure in removing the guiding catheter nasally by using a pharyngeal loop assembly.